//
/******************************************************
        File name:    main.c
        Author:       Bitat (陆叁柒)
        Gitee :       https://gitee.com/bitat
        Email :       737166381@qq.com
        History:      2023/1/4
*******************************************************/


#include <stdio.h>

int main()
{
    int i = 0;
    float arr[5] = {0};
    float sum = 0;
    for(i=0; i<5; i++)
    {
        scanf("%f",&arr[i]);
        sum+=arr[i];
    }
    printf("%0.2f\n",sum/5.0);
    
    return 0;
}
